Is it wrong that this reminded me of Monty Python and The Holy Grail, the bring out your dead scene.

I don't know. I was thinking more about one of the first MythBusters episodes, where they debunked the fact that you can be buried alive for days. It was shown that you may have hours at most, assuming that the coffin didn't cave in first (which it did, and I think it was pretty strong steel).